1. Field of the Invention
This invention relates in general to tamper evident packaging, and more particularly to a self-locking container for small parts which, although it can be reclosed for storage, once accessed provides visual evidence of its opening and cannot be relocked. Unauthorized opening of the container can thereby easily be detected.
Various applications for this type of container are contemplated. In Government, industry, and public use, electronic parts, memory chips, security keys, and other small devices must often be shipped and stored securely, and be easily identifiable. These parts often contain information which, if disclosed to unauthorized persons, could be harmful to national or corporate security. Many times the danger lies not in access to the device itself, but in the possibility that if access remains undetected, adversaries can exploit information from the equipments in which these electronics ultimately reside. With knowledge of the technology and codes contained within the electronics, or by simply having undetected access to an ordinary house key, would-be criminals can continue unnoticed. Thus, there is a need for a storage system which will enable detection of unauthorized access, is inexpensive to manufacture, and provides sophisticated protection for delicate electronic components.
2. Description of the Prior Art
Many tamper evident packages are known in the prior art. Many of these packages are designed to protect food or drugs from unnoticed contamination, as disclosed in U.S. Pat. Nos. 4,711,363, 4,474,305, 4,934,557, and 4,658,980, using an external tear off strip or tab. This type of container provides a level of protection sufficient for the unsophisticated tamperer, but the external nature of the locking mechanism provides direct access so that with the proper tools, such devices can be opened and resealed without obvious visible signs of pilfering. Such containers may not be self locking, so sealing might be impractical for users of a relatively small number of such containers, or for those who will be packing items at remote locations. Further, these inventions do not provide for protective packaging of small, delicate parts.
Magley's U.S. Pat. No. 4,785,963 discloses a "Tamper-Evident Buttress Plug Closure" which is designed for sealing closed a plastic 55-gallon drum. As the plug is threadedly advanced onto the outlet neck of the drum, it first engages the threads, then the ratchet on the neck. Frangible elements connect the ratchet ring to the outlet neck. In order to remove the plug, the frangible elements must be broken to disengage the ratchet mechanism, using a separate tool. In addition to being designed for different materials for different purposes, the present invention requires no separate ratchet ring, nor a preparatory action to disengage the closure, rather the lid ramps function both as ratchet teeth and as the tool to break off frangible elements.
U.S. Pat. No. 4,771,923 to Zinnbauer describes a "Tamper Evidencing Cap" designed to allow liquid to dispense from a bottle. The device includes a removable part connected to the exterior of the cap by frangible elements which are broken by unscrewing the cap thereby allowing liquid to pour through the opening. The Zinnbauer device provides external access to the tamper indicating mechanism and does not provide for protection of delicate solid material objects.
Although Towns and Brown provide internal tamper evidencing means in their U.S. Pat. No. 4,793,504, the closure relies on a cap liner membrane which is torn with the cap opening movement. The liner is made of a separate materials and requires relatively complex manufacturing processes.
More similar in its nature is the "Self-Locking Pilfer Proof Tamper Evident Container" as disclosed in U.S. Pat. No. 4,493,433 to Sideri and Del Brocco. The design of the Sideri, et al. container provides a physical barrier against opening of the container using interlocking tabs. Once engaged, the tabs cannot be separated. Once locked, access to the package requires substantial physical force, which could damage delicate electronic components. The Sideri, et al. package is destroyed upon opening, and cannot be used for storage after one use. The invention contemplated here utilizes a twisting motion of tabs against a barrier via the unscrewing of the two parts of the device. This provides an obvious stress pattern on the broken tabs and protects against a sophisticated adversary replacing the tab to hide evidence of tampering. After its first use, the instant invention can be reassembled for storage, and fitted with a high security tape which will provide a lower level of security during storage.
Although the prior art contains many patents which provide some level of protection against casual physical tampering, none has incorporated design features to provide separate, fitted partitions to hold delicate, or oddly shaped items while protecting against adversaries seeking electronic information from the items stored within them.